US East Coast Nuclear Plants Ready for Irene

Nuclear plants in Irene’s path are continuing their operations as workers strived to secure loose equipment, check diesel fuel supplies for backup generators and stow cots and food for workers who may be stranded inside the plants during the storm.

There are more than a dozen nuclear reactors along the U.S. East Coast: they are all undergoing safety procedures for the risk of potential loss of power and damage from high winds and storm surges as Hurricane Irene bears down on the region.

Though Irene has been downgraded to Level 1 – from 5, when it started moving northward – it still represents a risk and a threat for the many nuclear plants in the area.

More than 65 million people from North Carolina to Maine live in the projected path of the storm. The storm’s winds pose a greater threat to the switch yards and power lines that support a nuclear plant than the reactors themselves. These sit beneath containment structures of steel- reinforced concrete: they have been able to withstand an earthquake, they sure can face a hurricane. Damages to the outer power lines or to control systems in general might end up causing problems to the plants, though, with the need to power them down.

Federal rules require nuclear plant operators to shut down reactors as hurricane-force winds approach. If lesser winds cut power to a station, nuclear reactors are designed to automatically shut down and switch to backup power to keep in a “safe shutdown condition,” cooled to less than 300 degrees Fahrenheit, two hours before hurricane-force winds strike.

To comply with such rules, plant operators typically begin shutting down reactors 12 hours before winds exceeding 74 miles per hour are predicted to arrive.

Although Irene’s storm surge is expected to cause widespread flooding in coastal areas, it shouldn’t carry the destructive force of the Fukushima tsunami.